Manganese-base brazing alloys



' 3,124,451 MANGANESE-BASE BRAZING ALLOYS Arthur '1. Cape, Monterey, Califi, assignor to Coast Metals, inc, Little Ferry, N.J., a corporation of Delaware No Drawing. Filed Jan. 4, 1962, Ser. No. 164,411 5 Claims. (Cl. 75-134) This invention relates generally to manganese-base brazing alloys, but has reference more particularly to brazing alloys of this type which are characterized by the fact that they do not age harden excessively at elevated temperatures.

In testing manganese-base brazing alloys containing less than 63% manganese, with the remainder substantially all nickel or cobalt, or nickel and cobalt, it has been found that such alloys suffer from age hardening effects. Such alloys harden to prohibitive values when heat treated at 1000 F. for 336 hours, but the hardening also occurs at lower temperatures, over a longer period of time.

I have found, as the result of extensive tests in age hardening such alloys, that if the manganese content of the alloy is increased to 63%, with the remainder of the alloy essentially cobalt or nickel, or cobalt and nickel, that a dramatic change in the susceptibility of the alloy to age hardening occurs, and that the alloy does not age harden to prohibitive values, ifthe manganese content is increased to any value within the range of from 63% to 73%. r

I have found, in other words, that alloys containing from 63% to 73% manganese, with the remainder of the alloy principally cobalt or nickel, or cobalt and nickel, do not harden to prohibitive values at temperatures of 1000 F. for prolonged periods In arriving at these conclusions, the following series of brazing alloys were tested, for age hardening. In each case, lap joint samples were prepared, each of which consisted of strips of type 304 stainless and mild steel, joined in lap-jointed relationship by these brazing alloys. The lap joint samples were examined in the as-received or asbrazed condition, and in their condition following heat treatment at 1000 F. for 336 hours. The microhardnesses represent averages of readings, five takenin the fillet area, and five in the joint proper. All of the hardnesses are based on 200 g. Knoop.

It will be apparent from the foregoing that when the manganese content of the alloy is increased to 63%, with the remainder essentially cobalt or nickel, or cobalt and nickel, that the alloys do not change in hardness to prohibitive values, that is to say, to values in excess of about 400, and that this is true within a range of from about 63 to about 73% manganese.

United States Patent 1 O 3,124,451 Patented Mar. 10, 1964 ice.

'2 If cobalt is used to the exclusion of nickel, the cobalt may vary from about 27% to about 37%. If nickel is used to the exclusion of cobalt, the nickel may Vary from about 27% to about 37%. If nickel and cobalt are employed in combination, the combined content of cobalt and nickel may vary from about 27% to about 37%.

The alloy may contain, optionally, small amounts, that r is to say, from 0.05% to 2% boron, the boron improving the flow properties of the alloy, to some extent. The boron may be incorporated in the alloy, in the process of manufacture of the alloy, in the form of cobalt-boron, iron-boron, nickel-boron, or manganese-boron, these alloys containing about 14% to about 20% of boron.

The alloys may contain one or more of the elements chromium, copper, silicon, iron, carbon, and molybdenum, but the aggregate or total amount of these should not exceed about 5%. The expression, the balance substantially all nickel and/ or cobalt, as used in the claims, is intended to include boron, in amounts up to 2%, and one or more ofthe elements chromium, copper, silicon, iron, carbon, and molybdenum, in a total amount not to exceed 5%. g

The alloys can be made preferably by melting the ingredients in a vacuum or in an inert atmosphere, casting the melt into an ingot, and then rolling or drawing the ingot, or the alloys can be made by sintering together the constituents of the alloy. The alloys can also be atomized (melted and sprayed) with water or air.

The alloys have exceptional strength at high temperatures, and have excellent ductility.

A preferred specification for the alloys of this invention, within the indicated ranges is as follows:

Percent Manganese 63.0-69.0 Nickel 14.0-18.0 Cobalt 14.0-18.0 Boron 0.05-1.1 Silicon max 1.0 Carbon max .06 Other elements max 1.0

A preferred alloy, within the foregoing specification, is one containing about 65% manganese, about 16% nickel, about 16% cobalt, with the remaining 3% consist ing of small amounts of boron and silicon, and one or more of the elements chromium, copper, iron, carbon and molybdenum.

A typical alloy within the foregoing specification con- .sists of about 68% manganese, about 16% nickel, about 16% cobalt, and about 0.06% boron.

This application is a continuation-in-part of my copending application Serial No. 85,186.

Having thus described my invention, I claim:

1. A brazing alloy consisting of about 68% manganese, about 16% nickel, about 16% cobalt, and about 0.06% boron.

2. A brazing alloy consisting of the following elements,

within the ranges stated:

3; A brazing alloy consisting of about 68% manganese, about 16% nickel, and about 16% cobalt, said alloy being resistive to substantial age hardening at temperatures of 1000" F. for prolonged periods.

4. A brazing alloy consisting of about 63 to about 69% manganese, about 14 to about 18% nickel, and about 14 to about 18% cobalt, said alloy being resistive to substantial age hardening at temperatures of 1000 F. for prolonged periods.

5. A brazed structure consisting of ferrous metal parts and a brazing alloy joining said parts, said brazing alloy consisting essentially of manganese in amounts of from References Cited in the file of this patent UNITED STATES PATENTS 2,133,291 Gordon Oct. 1 8, 1938 2,339,252 Dean Jan. 18, 1944 2,850,381 Bolkcom et al. Sept. 2, 1958 2,856,281 Cremer et al. Oct. 14, 1958 2,872,309 Bolkcom et al. Feb. 3, 1959 

2. A BRAZING ALLOY CONSISTING OF THE FOLLOWING ELEMENTS, WITHIN THE RANGES STATED:
 4. A BRAZING ALLOY CONSISTING OF ABOUT 63 TO ABOUT 69% MANGANESE, ABOUT 14 TO ABOUT 18% NICKEL, AND ABOUT 14 TO ABOUT 18% COBALT, SAID ALLOY BEING RESISTIVE TO SUBSTANTIAL AGE HARDENING AT TEMPERATURES OF 1000*F. FOR PROLONGED PERIODS. 